Closed and open fire control mechanism



Feb 10, 1959 c. E. slMPsoN w 2,872,349

- cLosEn AND oPEN FIRE: CONTROL MECHANISM Filed my 11, 195s e sheets-sheet 1 R. 0 vw r J i2 a ww Z m om w. @Q NQ m r K hm. mm. `\N o Bl ETEN DE E- HTTORNEY-f.

,Il 2| n.. Om m NO In-. r r -ommdm NQ a@ E, o Nm mom) 1W 0m c. E. SIMPSON CLOSED AND 'OPEN FIRE CONTROL MECHANISM Feb. 10,1959

6 Sheets-Sheet 2 Filed Jiliy 11, 1956 4e 2o2 52 sov 70174 74 7e|54 IBI INVEI'VTOR. EICLDETIEE E- El THIJEI'L BY #wrom/ars.

Feb. 10, 1959 c. E. SIMPSON 2,872,849

CLOSED AND OPENYFIRE CONTROL MECHANISM Filed July 11, 1956 y 6 Sheets-Sheet 3 IN VEN TOR.

'mmm E- Eimpw'n Feb. 10, 1959 c.E. slMPsoN 2,872,849

CLOSED AND OPEN FIRE CONTROL MEOHANISM Filed July 11, 195e s sheets-sheet 4 Pigna- .INVENTOR E1n-Puna: E Elmpun I Feb- 19, 1959 vc. E. slMPsoN 2,872,849

CLOSED AND OZON FIRE CONTROL MECHANISM Filed July 11, 1956 6 Sheets-Sheet 5 INVENTOR. EIILTEHEE E E ITHPSDD BY Feb.` 10, 1959 c. E. SIMPSON 2,872,849

CLOSED AND OPEN FIRE CONTROL NECHANISM Filed July 11, 195e l e sheets-sheet e INVENTOR. ElllTE DEE E- EITIIFEUU BY v CLOSED AND oPnN Fmr: coN'rnoL MECHANISM Y Clarence E. Simpson, Wilbraham, Mass., assigner to the United States of America as represented by the Secretary of the Army The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to re control mechanisms for firearms.

With the wide variety of conditions under which light firearms are used in modern warfare, it is important that they be adaptable to as many conditions as possible with out requiring any major structural alterations.

It is, therefore, an object of this invention to provide for light rearms a re control mechanism which may be easily switched between automatic and semiautomatic tire.

It is another object of this invention to provide for light firearms a re control mechanism which has the advantages of tiring from a closed bolt position during semiautomatic re, for precision shooting, and from an open bolt position during automatic lire to reduce the danger of cook-oit when the rearm is stopped in a closed bolt position `after a burst of automatic lire.

It is a further object of this invention to provide for a light firearm la fire control mechanism which may be operated by a conventional trigger means positioned at the forward end of the receiver or by a trigger means at the rear of the receiver when the conventional trigger is not accessible because of mounting conditions as when mounted on a bipod or a tripod.

lt is a still further object of this invention to provide for light firearms a lire control mechanism having a pistol grip with conventional trigger mechanism for shoulder tire which is readily removed from the gun when hindering the'mounting thereof.

It is another and still further object of this invention to provide a tire control mechanism wherein the automatic sear acts as a safety to prevent the operation of the tiring mechanism until the bolt is locked 1in battery position.

The speciiic nature of the invention as well as other objects and ladvantages thereof willV clearly appear from a description of apreferred embodiment as shown in theaccompanying drawings in which:

Fig. 1 is'a partially cross-sectionedelevational View showing the fire control mechanism regulated to lire semiautomatically from closed bolt position by the trigger and the bolt in battery position but not locked therein by the locking sleeve; Y

Fig. 2 is a view taken along line Z-Z of Fig. l;

Fig. 3 is a view similar to Fig. lvbut shows the sear disconnected from the trigger by the selector;

Fig. 4 is a view similar to Fig. 2 but shows the arrangement of the parts when the bolt is locked in battery position; f

Fig. 5 is a View taken along line 5--5 of Fig. 4;

Fig. 6 is a view similar to Fig. l but shows'the fire control mechanism regulated to lire automaticallyffrom open bolt position with trigger control `and the bolt releasably held in recoil position;

Fig. 7 is a view similar to Fig. 6 but showing the bolt released and in battery position;

Fig. 8 is a view similar to Fig. l but showing the fire control mechanism regulated to re automatically from a closed bolt position and the bolt in battery position;

Fig. 9 is Va view similar to Fig. 8 but showing the tiring pin actuated by the hammer;

Fig. l0 is a partially cross-sectioned elevational view of the receiver with the pistol grip assembly removed and the lire control mechanism regulated to re automatically from open bolt position and the bolt releasably held in recoil position;

Fig. ll is a view similar to Fig. 10 but showing the bolt release actuated to release the bolt; and

Fig. l2 is an enlarged exploded View of the hammer and secondary sear mechanisms.

Shown in the iigures is a light firearm having a tubular receiver 12 which is terminated at the rear end by a shoulder fitting butt section to form the stock of the firearm. A barrel 16 is mounted to the front end of receiver l2 and a hollow, open-top pistol grip housing 18, which assists in manually supporting and aiming the firearm, is detachably mounted to the bottom side of such receiver by means of a conventional slot andtongue device at the front and a catch at the -rear end of such housing. A longitudinal slot 19 provides communication between the interior of receiver 12 and the interior of pistol grip housing 18. A bolt 2t) is Slidably mounted within receiver 12 and is actuatable to a recoil position along the longitudinal axis of such receiver by a conventional gas-operated device (not shown). Bolt 20 is biased to a battery position by suitable spring means and is locked in battery position by a locking sleeve 26 which is rotatable to an unlock position by the gas-operated device and to a lock position by such device when such bolt is in battery position. Slidably mounted through bolt 20 is a tiring pin 28 having a cartridge striker portion 30 and an extension portion 32 which protrudes from the rear end of such bolt.

Provided in the rear portion of receiver 12 is a recoil buffer assembly 34Vwhich absorbs the recoil forces in bolt 20 when in recoil position and which includes a plunger 36 engageable by such bolt, a spring 38 for resisting rearward movement of such plunger, and a cylindrical housing 40 for such plunger and spring. Extending through the front end of plunger 36 for a purpose to be described hereinafter is a vertical slot 41. p

Extending forwardly from the front end of housing 40 and along the lower inside portion of receiver 12 is a pair of laterally-spaced ribs 42 which are xed to the `in side of such receiver as bywelding and which extend vertically upward to form a trough 44 therebetween. The front ends of ways 42 are terminated by inwardly facing lip portions 46 which are located at a position which is rearwardly of the rear end of bolt 2) when in battery position. Placed in trough 44 is a hammer assembly 4S which lies below the path of bolt 2'0. Hammer assembly 48 is provided with a'rectangular housing 50 which is substantially the same width'as trough 44 so as to be restrained against'lateral displacement. The front end of buffer assembly housing 4l) and lip portions 46 restrain hammer assembly 43 against longitudinal displacement. Suicient longitudinal space is provided, though, to permit the rear end of hammer yassembly 48 to be pivoted upwardly. t t

Extending rearwardly into housing 50 from the front end thereof is a longitudinal opening 51 comprised of a rearward bore portion 52, which is terminated by a' wall 54, and a T-slot 55 extending forwardly therefrom. VThe front end of housing 50 is bifurcated by a vertical slot 56 and the front of the tine portions 58 formed by suchA slot have respective engagement with lip portions 46.

The ends of tine portions 58 are arcuately formed in the vertical plane so as to reduce the area of engagement between such tine portions and lip portions 46 as the rearend of housing t) is raised and lowered. A carrier of T-configuration is slidably mount-ed in T- slot 55 and such carrier is bifurcated at the front end by a slot 62, which is similar in width to slot 56, to form a bifurcated portion 64. Received by opening 51 is a cylindn'cal plunger 66 having a central portion 68 which has sliding engagement with the surface of bore 52 and a rearwardly extending rod portion of smaller diameter. Provided in bore v52 is a compressible coil spring 72 which engages wall 54 at one end and receives rod portion 70 at theopposite end to engage the adjacent side of central portion 68 so as to bias such plungerforwardly. Anotherrod portion 74 extends forwardly from central portion 68 to be slidablyreceived by an axial aperture through carrier 60. Rod portion 74 is slightly longer than carrier 60 and is terminated by a diametrically disposed face 78. A pin is rotatably received by a pair of laterally disposed holes 82 in bifurcated portions 64, and the ends of such pin extend beyond carrier 6) to be received by a pair of elongated longitudinally disposed slots 84 in housing 50 to limit the movement of such sleeve therein. Mounted on pin 80 in slot 62, as by press fit, so as to secure such pin against lateral displacement is a hammer 86 which is at in Vcontigui-ation and of substantially the same width as slots 56 and 62. Hammer 8 6 is provided with a body portion 88 having a hole 90 therethroughto receive pin 80. An arm portion 92 extends upwardly and forwardly from body portion 88 to be engageable with extension portion 32 of tiring pin 28 for actuation thereof to fire a cartridge chambered in barrel 16.

The top Vside of arm portion 92 inclines upwardly and forwardly and is cammingly engageable with the rear side of slot 56 so that such arm is moved downwardly to be received by T-slot 55 as carrier 60 is retracted within housing 50 to a cock position. Provided on the rear side of Vbody portion 88 is a at'94 which, when fully engaged with face 78, resiliently holds arm portion 92 iipwardly in position to engage tiring p in 28, and a projecting ledge 95 on the top side of flat 94 is engageable with rod 74 to secure hammer 86 against rearward rotation when firing pin 28 is struck thereby.

Extending rearwardly into housing40 from the front end thereofis a triangularlike, vertically disposed recess 96 which is provided with a top side 98 that inclines rearwardly and downwardly from the f ront end of such housing and which is arranged to receive a tongue 188 f.:

mer housing. A flat spring 102 is mounted in recess 96 to f' engage the bottom side of tongue and bias hammer assembly 48 upwardly until such tongue engages top side 98 of recess 96.

A rectangular bar 104 is mounted for, longitudinal, non-rotating .movement through a pair of longitudinal bosses 106 xed to the inside of receiver 12 on the left side thereof. The front of bar 104 is terminated by a face V188 which hassliding engagement'with the rear end of locking sleeve 26 away from the axis thereof. The rear end of bar 104 is terminated adjacent sleeve 68 by amounting portion 110 which protrudes outwardly into a hay 112 extending from receiver 12. Extending laterally through mounting portion 110 is an elongated opening 114jwhich isv transversed by a vertical pin 115 adjacentthe front end of such opening a'nd alignment with the outside'surface ofbar 104.v

A s ear member,1 hereinafter 'referred to as secondary ser 1 16, is mounted for pivotal movementon pin 115 andincludes an arm portion 118 ywhich is extendable through an elongated slot 129 in housing 58 for'releas.

able engagement with catch portion 122 in carrier 60. Inward movement of arm portion 118 beyond engaging position is prevented by the engagement of a dat 124 on the front portion of secondary sear 116, inward of pin 115, with the front end of such flat. Secondary sear 116 is biased to engaging position by a flat spring 126 which is mounted to the inside surface of the adjacent one of the ribs 42 forwardly of bay portion 112 and is arranged to resiliently engage the outside surface of arm portion I 118. When secondary sear 116 is in engaging position and face 10S is engaged with the rear face of locking sleeve 26, the front end of slot is engaged with the rearwardly and inwardly extending inside surface of such arm portion noted at 127.

Provided in the rear side of locking sleeve 26 and in alignment with bar 104 is a notch 128 which permits bar 104 to be moved forwardly by the bias of coil spring 72 which is transferred to such bar by the engagement of arm portion 118 with catch portion 122. However, during such forward movement of bar 104, secondary sear 116 carried thereby is cammed out of engagement with catch portion 122 by the sliding engagement of the front portion of slot 120 with the inside surface 127 of arm portion 118. Cam portions 129 and 130 on the front end of bar 104 and on one side of notch 128, respectively, cooperate to move such b ar out of such notch during rotation of locking sleeve 26 to unlock bolt 20.

Provided in the front end of piston grip assembly 18 is a trigger guard portion 131 which forms an opening 132. Extending transversely through piston grip assembly 18 above opening 132 is a pin 134 and pivotally mounted thereon is a trigger 136 having a body portion 138 provided with a hole 140 through the front end thereof to receive pin 134. A linger piece 142 depends from the rear of body portion 138 into opening 132. Provided in the top rear portion of body portion 138 is a recess 144 having a substantially vertical front side 146 and a bottom side 148 which extends rearwardly therefrom at an angle which is slightly more than 90. A pin 150 extendslaterally through body portion 138 so as to pass through the front side of recess 144. Pivotally mounted on pin 150is a disconnector 152. Such disconnector is provided with a leg portion ,154, ,which extends upwardly into receiver 12 through slot v19, and a foot portion 156 which extends rearwardly therefrom at an angle of approximately 9 0 l in 150 is mounted transversely Vthrough disconne'etor 152 at the junction of leg portion 154 and foot portion 15 6. v As ythe angular relationship of front side 146and bottom side 148 is slightly more than 90, and that o f .leg portion 154 and foot portion 156 is approximately 90, such d isconnector is pivoted between engagement of such legportion with such front side and engagement of such foot portion with such bottom side. Extending downwardly into body portion 138 isa bore 160 and received therein -is a plunger 162 which is spring-biased against the bottom side of foot portion 156 to pivot leg portion 154 forwardly by a spring 164.

Extending transversely through tne top of pistol grip assembly 18, adjacent the front end of housing'50, is a pin 166 which provides a pivotal mount for asubstantially linear Sear 170. Sear 170 is provided with an engaging portion 172, which extends rearwardly from pin 166 to be engageable with a catch rportion 174 in the bottom side of carrier 6 6 to rcleasably hold hammer 86 in a cock position slightly rearward of the automatic cock position held thereby by secondary sear 116, vandan actuator portion 176 which extends forwardly along slot 19. Provided in actuator portion 176 is a vertical slot 178 which receives therethrough leg portion 154 of disconnector 152 and permits limited pivotal movement thereof. A coil spring 179 resiliently rotates se'ar 170.tomove engaging portions 172 upwardly in positionto engage catch portion 1 74.

i The Vtop fronty portion of leg portion 154 is cut away, as noted at 180, to form a ledge 182 at the bottom side and such ledge is engageable with the bottom side of actuator portion 176, forward of vertical slot 178, when disconnector 152 is in normal forward position.

Whereby, when finger piece 142 is pulled rearwardly, disconnector 152 is moved upwardly, by being mounted rearwardly of the pivotal point of trigger 136, and with ledge 182 being in engagement with the inner side of the forward actuator portion 176, such actuator portion is moved upwardly to pivot engaging portion 172 downwardly out of engagement with catch portion 174 to release hammer 86. A cam surface 184 extends upwardly and rearwardly from the rear side of cutaway portion 180 for a purpose to be hereinafter explained. i

Mounted transversely through receiver 12 above trigger 136, so as to cooperate with disconnector 152 as hereinafter described, is a selector 186. Selector 186 includes a rod portion 188, which isrotatably mounted transversely through receiver 12 by means of suitable holes therethrough, and a suitable handle means is fixed to one end of such rod and is located on the outside of such receiver. Selector 186 is so disposed in cooperation with disconnector 152 that when such disconnector is moved upwardly by finger piece 142, cam surface 184 cammingly engages the perimeter of rod portion 188 to pivot leg portion 154 rearwardly and so move ledge 182 out of engagement with actuator portion 176 and permit spring 179 to rotate sear 170 into position to reengage such catch portion during the next cycle of operation. However, a segmental portion 191 is cut out of rod portion 188 so that when selector 186 is rotated to move such segmental portion adjacent leg portion 154, cam surface 184 is not engageable with such rod portion to cam such leg portion rearwardly. Therefore, ledge 182 remains in engagement with sear 170 and engaging portion 172 held down out of engagement with catch portion-174 so long as finger piece 142 is held rearwardly.

A pin 192 extends laterally through piston grip houseing 18 rearwardly of sear 170 and provides an axle for a trip lever 194 pivotally mounted thereon. Trip lever 194 includes a front portion 196 having a front end which has engagement wtih bottom side 148 of recess 144, and a rear portion'198 the end of which is received by a hook portion 200 which depends from the bottom of housing 50. Whereby, when finger piece 142 is pulled rearwardly, bottom side 148 is moved upwardly to pivot -rear portion 198 downwardly moving with it against the bias of spring 102 the rear end of housing 50.

Projecting upwardly from the rear of the top side of housing 50 is adivided lug 202 which is engageable with a stop portion 204 on the rear end of bolt 20 Yfor holding such bolt in the recoil position when the rear end thereof is in a normal upward position and -is disengaged therefrom when rear portion `198 of trip lever 194 pullssu'ch rear end downwardly through a rearward pull on'iinger piece 142. A cam surface 205 on the front end of lug portion 202 provides the meansfor depressing such lug portion out of the way during recoil flight of ybolt 12. The rear end of housing 50 may also be moved downwardly to disengage lug 202 from stop portion 204 by a bolt release 206 which is mounted for slidable vertical movement through a hole 208 provided in a mounting portion 210 extending forwardly from the top front side of housing 40 and through slot 41 in plunger 36 to en-v gage the top side of housing 50. A lock 212 is slidably mounted on the outside of receiver 12 for cooperation with bolt release 206 to selectively lock such bolt revlease in a down position whereby the rear end of housing 50 is held downwardly so that stop portion V204 is not engageable by lug 202. v

Operation When the rearm is to be fired automatically from open bolt position and through the control of finger piece 142,

selector 186 is turned to rotate rod portion 188 so that segmental portion 191 is adjacent leg lportion 154 of disconnector 152 and the rear end of housing 50 is .released from depressed position by unlocking lock 212 whereby spring 102 biases such rear end upwardly. With the rear end of housing 50 in elevated position, hook 200 raises rear portion 198 of trip lever 194 and lowers front portion 196 into engagement with bottom side 148 of recess' 144.

Bolt 20 is then retracted by charging means (not shown) until stop portion 204 thereon is engaged by lug portion 202 on housing 50 to releasably hold such bolt in the recoil position. When bolt 20 is retracted to the recoil position, the end of hammer 86 is engaged by the rear end of bolt 20 after which continued rearward movement of such bolt causes arm portion 92 of such hammer to be cammed downwardly and rearwardly by engagement of the top side of such arm portion with the rear side of slot 56 into T-slot 55 to press carrier 60 against coil spring 72 to permit bolt 20 to pass by. Hammer 86V is held Within T-slot 55 by the engagement of secondary sear 116 with catch portion 122 and arm portion 92 held downwardly by the sliding engagement of the end thereof with the bottom side of bolt 20.

When the firearm is to be fired, nger piece 142 is pulled rearwardly whereby bottom side 148 of recess 144 is pivoted upwardly carrying with it front portion 196 `of trip lever 194. Consequently, rear portion 198 is pivoted downwardly depressing the rear end of housing 50 to release stop portion 204 from lug 202. Whereupon, bolt 20 is released to be biased to battery position by suitable spring means, which were energized by such bolt during flight to recoil position, and during such forward movement a cartridge is picked up from a feeding mechanism (not shown) andchambered in barrel 16.

After the rear end of bolt 20 passes over hammer S6 in going to battery position, arm portion 92l is freed to be biased upwardly into position to actuate firing pin 28. However, hammer 86 is prevented from striking firing pin 28 because of the engagement of secondary sear V116 with catch portion 122 in carrier 60, which slidingly lcarries such hammer, as sear 170, which would have engaged such sear before such secondary sear, is pivoted out of the way by the upward position of disconnector 152 while finger piece 142 is held rearwardly.

Until bolt 20 is in battery position and is locked therein by rotation of locking sleeve 26, hammer 36 remains cocked by secondary sear 116. However, when locking sleeve 26 is rotated so that bolt 20 is fully locked, notch 128 is aligned with bar 104. Therefore, bar 104 and secondary sear 116 are moved forwardly by the bias -of coil spring 72 transferred thereto by the engagement of arm portion 118 with catch portion 122 and during such forward movement 'arm portion 118 is cammed out of engagement with catch portion 122, freeing carrier 60 which moves hammer 86 forwardly to Strike firing pin 28 and fire the chambered cartridge.

With the ensuing recoil of bolt 20, the same action takes place as previously described for the charging operation and the firing cycle continues until finger piece 142 is permitted to return to normal forward position. Whereupon, spring 102 biases the rear end of housing 50 upwardly in position for lug 202 thereon to engage stop portion 204 on bolt 20 to stop the iiringrcycle and releasaoly hold such bolt ready to fire another cartridge when finger piece 142 is actuated again.

VWhen the firearm is to be fired automatically from closed bolt position and with trigger control, bolt release 206 is'pushed downwardly to depress the rear end of housing 50 so that lug 202 thereon will not be engageable with stop portion 204 and then locked in down position-by lock 212. With the rear end of housing 50 in down position, front portion 196 of trip lever 194 is pivoted out of engagement with trigger 136 and sol will not be actuatable thereby. Selector 186 iseposi-J attrae-1s J tionedo thatsegmental portion 191 is adjacent leg portion 156 ofdisconnector 152. t v

Theffirearm is charged by manually actuating bolt 2t) to recoil position andythen returned to battery position to pick up and chamber a cartridge from the feeding mechanism (not shown). During lrecoilutravel of bolt Zt, hammer 86 is 'retracted into T-slot 55, as hereinbeforeV disclosed, vto be ireleasably, engaged by Sear 170 to cock such hammer. Thus, when finger piecelliznis pulled rearwardly to fire the firearm, disconnector 152 is moved upwardly vagainst actuator portion U6 of scar 170 to pivot engaging p ortion 172 downwardly to release carrier d which, through the bias of the loaded coil spring i712, moves hammer 36 forwardlyv to strike firing pin 28 for firing the chambered cartridge. Asbolt 2% finished in a locked battery position when the charging was completed, secondarysear 1116 was automatically biased to the disengaged position, as hereinbefore de scribed, and so out of position to intercept movement of hammer $6. y g y During the resulting recoil of, .bolt 2t), hammer 86 is retracted, as hereinbefore described, and Yso long as tinger piece R42 is held rearwardly for continued fire and sear 1,701., is, consequently, held out of engagement with carrier 61"?. Such' carrier will be cyclicly engaged during movement of such bolt to battery position by secondary sear fito and automatically released therefrom when bolt 2i? is locked in battery position. Firing will continue until the ammunition is depleted -or finger piece 142 is released to return to normal position. Whereupon, Sear 171i is positioned to engage carrier 60 before secondary scar M6 and thereby stop the firing and releasably hold hammer 86 ready to resume firing when finger piece 142 is againretracted. To fire the firearm semiautomatically from closed bolt position and with trigger control, selector 186 is rotated so that the perimeter of rod portion 183 will be engageablc by cam surface T184 on leg portion 154. Therefore, with the firearm charged and hammer 86 cocked by sear 170, a rearward pull on nger piece 142 causes disconnector 152 to be pivoted upwardly to actuate Sear 170 for releasing hammer S6 to fire the chambered cartridge. However, during upward movement of leg portion 154, cam surface 184 thereon engages rod portion 18S to cam such leg portion rearwardly and thereby disengages ledge 182 from scar E70 after such sear is actuated to release hammer 86. After being released from disconnector 152, s ear ltl. is biased by coil spring 179 so that engaging portion 172 is in position to engage catch portion i745 of'carrier'6t and cocli hammer 86. To firek another cartridge, finger piece 42 will haveto be retracted again, and it is obvious that the operator will not be able to fire the 'firearm until bolt 2G is in locked battery position as secondary YSear 116 will Yremain in position to engage carrier 6i) and stop hammer S6, after being released from scar No, until locking sleeve 2.6 is in full locked position. Then, as hereinbefore described, secondary sear M6 will release hammer 86 automatically to fire 4the chambered cartridge. it is obvious, therefore, that secondary scar 1?;6 also acts as a'safety as it prevents the firing of a cartridge until bolt 20 is locked in battery position.

When the mounting of the firearm makes it impossible or difficult for the operator 'to .actuate finger piece 142er if pistol grip housing 1S is in Athe way, such pistol grip housing is removed and withit Athe components mounted therein. Lock 212 is then actuated'to release bolt release 266. When bolt release l2do is released, Vthe rear end of housingrStl is released to be biased upwardly by fiat spring 102 so that lug 202 on such housing will be'engag'eable with stop portion 26d on bolt'Z.v Thus, when the firearm is charged, bolt 26 is releasably-helcl in recoil position by housing V:5th,andhthejfiringA of the rearm is controlled by bolt release 206.,To fire the firearm, bolt release 206 is pressed downwardly to re- 8 lease bolt 20 which goes forwardly to battery position and, when locked therein by locking sleeve 2'6, secondary 'se'ar 116willeautoinaticallyrelease hammer 36 to 'fire the chambered cartridge, `as hereinbefore described; To stop firing, pressure is released fromV bolt-release i206 whereby the bias of iiat spring lill elevates the rear endrof housing 50 to engage bolt 12v during recoil iiight.

The firearm may be fired bybolt release 206 without removing' pistol grip housing 13 if provision is made to lock finger piece 146 in a retracted position soas to maintain scar i7@ out of bolt engaging position,

From the foregoing, it is clearly apparent thatA there is herein provided a novel firing mechanism which is readilyadapted for many types of operation, which provides a member which is bothk an automatic Sear and a safety to prevent ythe firing 'of a cartridge before the bolt is locked in battery position and which is simple andfrugged in construction. Y

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof `and the following claims are intended to include 'such variations.

I claim: A Y y l. ForV a firearm provided with a boit reciprocable between a` recoil and a battery position, a sleeve for rotatably .locking the bolt in the battery position and a tiring pin-,slidingly mounted in the bolt, a fire control mechanism for selectively firing the firearm from open or closed boltpositio n and for automatic or semiautomatic operation including a hammer biased for lengagementrwiththe firing pin and actuated by the Abolt to a retracted position lduring'movement of the bolt to the recoil position, a-secondary seardevice for releasably heiding said hammer in the cocked position forwardly of the retracted position and being arranged for cooperation with said hammer for the automatic release thereof when the bolt is locked in batteryl position, a sear for releasably holding said hammer in the retracted position, a `detachable trigger device for actuating said Sear to release said hammer when heldl thereby, pivotal means for releasably holding the bolt in the recoil position for firing the Vfirearm from they open bolt position, lever means actuatable by said trigger device for pivoting said pivotal means to release the bolt and to hold Asaid lever means away from theV boltholding position to 'effect automatic iring by said secondary sear device, and a bolt release member for pivoting said pivotal means when said trigger'device is detached from the firearm to i hre the firearm automatically Vand to 'hold said lever means away from the bolt holding position .to enable semiautomatic firing from closed bolt position through the cooperation ofsaid sear and said trigger device.

l2. For .a firearm provided with a 'bolt reciprocable between a recoil and a battery position, a sleeve for re'- leasably locking the bolt in 'the battery position and a firing pin slidingly, mounted in the bolt, a fire vcontrol mechanismffor selectively Vfiring the firearm yfrom a closed or open bolt-position and-for yautomatic or lsemi'aiitt'imatic operation 'including'a hammer biased for engagement with the firingpinand being retractableby'the boit to a retracted-*position during movement of the bolt to the 4recoil position, a secondary sear device coop/rable with the locking sleeve for releasably holding s'aid'hamin'e'rfin va Acocked positionfforwardly of the retracted position and with said hammer'for the` automatic release thereof whenV the bolt is llocked in battery position for aritomaticroperation of the firearm, a scar for releasably engaging said hammer when in the retracted position and the boit is in the battery position to 'firethe -firearm from closed bolt position and Withsemiautomatic operation, a detachable trigger device fractuating saidV seat to release said hammer, "pivotal means for releasably holdingtthe-bolt in the recoilpositio-n to operate the firearm Vfrom open boltpos'ition, 'lever means -actu'atable scar, and disconnecting means for disconnecting said trig ger device from said sear after the release of said hammer by said trigger device and for reconnecting said trigger device to .said sear to elect semiautomatic iire.

3. For a firearm provided with a receiver, a bolt slidingly mounted in the receiver for reciprocation between a recoil and a battery position, a firing pin slidingly mounted in the bolt and a locking sleeve for rotatably locking the bolt in the battery position, a tire control mechanism including means for selectively tiring the tirearm automatically .or semiautomatically and from an open or a closed bolt position comprising a longitudinally disposed hammer housing mounted for pivotal movement in the receiver, spring means for resiliently pivoting said hammer housing to an engaging position, cooperating latching means on said hammer housing and the bolt for releasably holding the bolt in the recoil position when said hammer housing is in the engaging position, a trigger mechanism detachably mounted to the front end ofthe receiver, lever means actuatable by said trigger mechanism for pivoting said hammer housing out of engagement with the bolt, a manually-operated bolt release slidingly mounted to the rear end of the bolt receiver for engagement with said hammer housing for actuation thereof to release the bolt, a hammer member slidingly mounted in a longitudinal opening in the front en'd of said hammer housing for engagement with the firing pin and for actuation by the bolt to a retracted position within said opening during movement of the bolt to recoil position, a spring mounted in said opening for biasing said hammer member against the firing pin when the bolt is in battery position, searmeans engageable with said hammer member and actuable by said trigger mechanism for iiring the firearm semiautomaticaily from a closed bolt position, and secondary scar means actuatable by said hammer member in cooperation with the locking sleeve for automatically releasing said hammer member to automatically iire the tirearm from open bolt positioniwhen said housing is held out of the engaging position by said trigger mechanism or said bolt release and to prevent the firing of the firearm when selected for semiautomatic operation until the bolt is in locked battery position.

4. The combination of claim 3 wherein said hammer device includes a carrier having a forwardlyextending bifurcated portion slidingly mounted in said opening,v a tine portion at the forward end of said housing formed by a vertical slot, a hammer member pivotally mounted on a pin extending transversely through said bifurcated portion, an arm portion on said hammer extendable through said slot for engagement with the firing pin,

plunger means slidingly mounted in said opening between said carrier and said spring so as to transmit the bias ot' said spring to said carrier, a rod portion extending slidingly through an axial Vaperture in said carrier for engagement with said hammer member, a flat on said hammer member cooperable with the engaging end of said rod for biasing said arrn portion into a position for engagement with the'firing pin, cooperating cam means on said arm portion and said housing for moving said hammer member into said opening when said portion is engaged by the bolt during movement to recoil position, and a ledge portion on said hammer member cooperable with said rod portion for preventing pivotal movement of said hammer member when actuating the ring pin.

5. The combination of claim 3 wherein said secondary sear means includes a bar slidingly mounted in the reeeiver and having one end slidingly engaged with the locking sleeve, a sear member pivotally mounted to the opposite end of said bar vfor releasable engagement with a catch portion in said hammer device when retracted by the bolt to releasably secure said hammer device in a cocked position and transfer the bias of said hammer de-` vice to said bar, a notch in the locking sleeve into which said one end of said bar is moved by the bias of said hammer device when the locking sleeve is rotated to lock the bolt in battery position, and cam means for moving said sear member out of engagement with said hammer device during movement of said bar into said notch.

References Cited in the tile of this patent UNITED STATES 'PATENTS 

